RunSynchronously may not be called on task that was already started

Question

I am having an issue with a c# class I created for unit testing my application, in particular the issue is around a System.Threading.Tasks.Task object.

I have a list of such objects and on them I want to execute each synchronously.

I call the following:

myTask.RunSynchronously();

When I do such, I am always getting the following error and I dont know why are how I can fix it.

System.InvalidOperationException: RunSynchronously may not be called on task that was already started.

Anyone got any ideas?

Solution 1

The problem is that you started the task when you call TaskFactory.StartNew - I mean, it's even in the name of the method that you are starting the task. StartNew creates the task, then calls Start on your behalf. =D

If you want, you can either Wait on the task, like @Peter Ritchie said, or you can create the task manually like so:

var task = new Task(() => { ... });
task.RunSynchronously();

Solution 2

It's already started, just use myTask.Wait()